I've heard trustworthy mechanics and even the guy at the local trans shop telling me that if I flush my fluid now I may loose the trans sooner than if I dont flush it. It is original with over 150,000 miles on it and not the right colour at all. So should I flush it? partial flush it at least? I'm afraid since the last time I flushed my trans fluid on a really high miles car the trans died within a month.

Basis of the claims is that the transmission actually needs the broken down metallic particals mixed with the fluid for everything to work properly, in my opinion I dont see how this is a true statement but the fact I had a trans died right after a trans flush has me a bit worried.

My trans is shifting perfect right now so I dont want to mess up a good thing. The fluid is a dark brown colour though.

My 93'* trans fluid was changed once a year and experienced an early trans failure around 100k so I'm a little worried. GM says change it at least every 100k, and if driving in stop and go traffic change it more often.

its gonna happen one way or another...so really, flushing it may or may not accelerate it. I would drop the pan and check and see what you've got. and if theres nothing bad in there, i would say definitely flush it. Just my opinion.

if the transmission is not slipping now, then the odds of the tranny failing after flush are minimal.

The reason that many mechanics give the advice as you heard is to cover their asses. Many people when the tranny starts to slip will change the fluid hoping that by some miracle everything will be fixed. On some of these occasions, the car doesn't drive itself out of the shop after the flush. Mechanics want people to know what they COULD be getting into.

Basically, if the tranny is close to dying, then yes, the flush will likely make it slip more. and if the transmission is still running good, then flush away, getting the grit out can only be a good thing on an otherwise healthy transmission

i also support dropping the pan regularly * maintenance every 30k mi or so

Any trans that failed because of a flush was going to fail anyway.

I've done high-mileage flushes on both my cars with great results. I have NEVER seen any actual proof that anyone ever crapped a trans from this. But there sure are alot of rumors..

You state your trans is perfect right now, which makes this post about something that'* NOT a mechanical issue.

Moving to General Chat.

Drop the pan; clean it; replace the filter and half the fluid. Do it again in a year. Safe and effective.

Being that there is a 150K on the car, I would take it somewhere and do a fluid flush. The flush will get 98% of the old oil out, while droping the pan will only get 30-40%.

Once you get the flush done, drop the pan and replace the filter.

Remember, no Jiffy Lube

Drop pan and filter change. Like BB says.

Personally, my trans made 175K with the last 45K being abused by me. At 130K it got it'* first pan drop, filter change and refilled. Right before WCBF (1 year later) I did it again.

You could do it say every 10K until the fluid looks good again and that way you'd be working the old fluid out slowly. Or you can do a full flush and have fresh fluid. Either way.. changing fluid is changing fluid. The fluid had detergents and additives that the transmission needs, currently your fluid is broken down and in poor overall shape. A fluid change as stated, does not cause a transmission failure. Other parts wearing in the transmission cause the failure.

After being on the phone with you... I'd save up for a new fresh, hard shifting trans. I'm loving mine.

We've had flushes on all of our 65E'* in my family, none have had issues. All of our cars were flushed at around 50k miles, and we've all put around 20,000 miles on our cars since the flush with zero problems. I recommend it. The transmissions seemed to shift more seamlessly after the flush, except for the Aurora. But that'* another story. It'* always shifted more firm for who knows what reason.

I had a Explorer a few years back and did a trans flush on it at 113,000 miles. About 6,000 miles later, I started losing second. I've been told "supposably" if you change your fluid over 100K and it'* never ever been changed, you run the risk of losing your trans. Now, yes my truck had never had a trans flush, and it went out shortly after. But, I think it was more of a coinsedence than anything. I'd honestly say change it. If the trans is gonna go, it'* gonna go either way.

This experience is similar to three that I have observed (friends and neighbors) where a transmission that was working fine was flushed for maintenance and failed shortly after. I believe the problem occurs when poorly trained or dishonest shops service transmissions without properly maintaining or operating the flushing and cleaning equipment. These personal observations have spooked me on having my trans flushed. Also, as I understand it, some flushing places don't even drop the pan, clean it, and install a new filter.

Changing half the fluid with no chance of destroying the transmission as a result seems a safer path to me.